1. Field of the Invention
The present invention relates to an outboard motor provided with an internal combustion engine including a cylinder block provided with cylinders in an in-line arrangement, a cylinder head, and an electrical equipment box holding electrical equipment therein. More specifically, the present invention relates to the layout of an engine body including a cylinder block and a cylinder head, and an electric equipment box.
2. Description of the Related Art
There has been known an outboard motor provided with an internal combustion engine including a cylinder block provided with cylinders in an in-line arrangement, a cylinder head, a vertical crankshaft having a vertical axis, and an electrical equipment box holding electrical equipment therein. A vertical plane containing the horizontal center axis of the outboard motor divides the internal combustion engine into an intake-side part and an exhaust-side part. The cylinder block is provided with an exhaust manifold passage. The electrical equipment box is placed in the exhaust-side part. This type of outboard motors is disclosed in, for example, Japanese Patent Application Publication No. 2-274689.
In case the electrical equipment box is placed in the exhaust-side part and the exhaust manifold passage is formed in the cylinder block, the disposition of the electrical equipment box near the cylinder head with respect to a direction parallel to the axes of the cylinders is obstructed by walls defining the exhaust manifold passages. Consequently, restrictions are imposed on the position and size of an intake system which includes an inlet air silencer and is disposed on the front side of the electrical equipment box positioned in front of the cylinder head. When the electrical equipment box is disposed transversely apart from the center axis of the outboard motor to avoid interference of the electrical equipment box with the intake system and the walls defining the exhaust manifold passage, the transverse width and the weight of the outboard motor increase.